An analyzing apparatus, for example, a thermal analyzing apparatus or the like measuring and analyzing a minute signal output from a detector is provided with a circuit board on which an amplifier amplifying the signal from the detector is mounted. Besides the amplifier, various elements such as an electric resistor and a capacitor are mounted on the circuit board.
When each element is mounted on the circuit board, for example, terminals provided in each element are connected to the circuit board by soldering or the like. At this time, since heterogeneous metals are connected to each other, a thermocouple effect occurs at the connection point, and thus, an electromotive force is generated at the connection point as the temperature changes. Such an electromotive force causes noise or drift, and in particular, the influence of the electromotive force cannot be ignored in a detection circuit detecting a minute signal (for example, refer to Patent Literature 1 described later).
In the related art, measures to avoid the occurrence of the above-mentioned electromotive force by performing thermal insulation around the circuit board, temperature control of the board itself, and increasing of the separation distance between the heat generation source and the important component have been taken.
[Patent Literature 1] Japanese Patent No. 2903005